1. Field of the Invention
This invention relates to an apparatus and method for identifying and distinguishing among automotive brake spiders. More specifically an apparatus is provided which measures certain critical dimensional characteristics which vary slightly from one brake spider to another to enable quick identification for replacement part selection purposes.
2. Description of the Prior Art
In automotive vehicles of conventional design, such as trucks, tractors, busses or trailers, it is a common practice to mount all the wheel brake mechanism, except the brake drum which rotates with the wheel, on a relatively stationary support plate known in the art as a brake spider. This brake spider is usually non-rotatably secured to the axle or axle housing either by being bolted to an intergral axle flange or welded directly thereto. Conventional brake mechanisms in vehicles of the class referred hereto consist in general of two internally expanding brake shoes pivoted or anchored by pins on one end of the brake spider, and the other ends of the brake shoes adapted to be spread apart for drum engagement by means of a rotatable brake actuating cam having a shaft or rod journaled in the end of the brake spider opposite the pivot points. The anchor end of the brake spider is usually provided with two spaced apart through bores or holes to receive hardened anchor pins of the brake shoes and the opposite end of the brake spider is provided with another through bore to receive a bushing or bearing to support the cam shaft.
U.S. patents showing typical brake spiders are U.S. Pat. No. 2,167,607 issued to H. W. Alden on July 5, 1939, U.S. Pat. No. 3,131,583 issued to W. G. Henley at al. on May 5, 1964 and U.S. Pat. No. 4,157,747 issued to Getz at al. dated June 12, 1979.
It has been found that there has been difficulty in assemblying and repairing brakes on the heavy duty vehicles listed above because of the difficulty in distinguishing between a variety of brake spiders which may differ only slightly but are not interchangeable. It has been left to the present invention to provide a means for quickly and accurately distinguishing between various brake spiders commonly used in truck braking systems. As far as is known to the inventor, no similar apparatus or method for identifying brake spiders exists.